\Slide{Analysis technique}{
  \B
  \item Override {\tt sawOpcode} (instruction-level visitor callback)
  \item Look for {\tt invokestatic} instructions
  \item Warn when
    \begin{enumerate}
    \item Class = {\tt java.lang.System}
    \item Method = {\tt gc}
    \item Signature = {\tt ()V}
    \end{enumerate}
  \E
}
